Fluid operated tool



Feb. 28, 1933. J. R. HOFFMAN FLUID OPERATED TOOL Filed Jan. 31, 1951 2 Sheets-Sheet l Zinnentor J/zrz J?- ifqffwwn attorneys.

Patented 1 33b. 2 3

UNITED PATENr OFF cE 1 JOHN nnormmn, or mmrson, Wisconsin, Assronon To MADISON-RIPE, CORPORATION, or MADISON, WISCONSIN, A CORPORATION OF WISCONSIN FLUID. OPER TED TOOL Application filed January 31, "1981. Serial No. 512,700.

. This. invention ielatesto fluid-operated tools and particularly to those ofthe'impact or percussive type.

' ther disclosing the same featu Primarily, it isthe object of my invention to provide for shop or generaluse a small, -but practical, high speed tool of the-cha-rfl {acter mentioned. I It is .propfosedjto make the tool of the lightest smetal possible, consistent with efiicien'cy,'-and to so designand shapeethetool as to adapt it; for one-hand manipulation by the operator.

An important feature of the tool is the eflicient utilization of the exhaust motive fluid from theimpact motor for operating the valve means for distributing the motive fluid to the-hammer cylinder. Rapid distribution of the motive fluid to the hammer cylinderand positiveyaction of the distributor valve are also important features of the device. a

A further feature contributing to the reliability and-efiiciency of operation of the tool is the special arrangement for distribu-., tion of .the motive fiuidywhereby greater {force is applied to thel-hammeron its working strOkethan on its return. Improved means for supplying lubricant .to the moving, parts of the tooll'also are provided A practical embodiment of the device is shown in the accompanyingdrawings,'in; which 1 I Fig. 1 is a side elevation of the tool with certain parts broken :awayito show the turbine. runner which operates thedistribu-tor valve; I

Fig. 2, a front elevation of the same;

Fig. 3, a. longitudinal .section' taken on line 33 of Fig. 4, showing the distributor. valve in positionto feed mot 40 ive fluid to the right .end of the hammer cylinder; Fig. 4, a transverse section on theqline 4- 1 of Fig. 3, with the distributor valve inth'e same position I g Fig. 5, a section taken ,-on line 55 of Fig. 3, showing the manner in which the exhaust fluid from the hammer cylinder operates the turbine runner;

Fig. 6,; a sectionon line f-6 re; r Fig. 7, a section taken on line -77 of Fig.

of Figs. 3 and 4;

,ing for holding means; and Fig. 14, ap 'from the tool. a

lated with aininimu slotted screw plugs 5, 6.

- other steel 9. In cross ber'7 and steel's'hank 8 p socket and thereb of Fig. 3, fun

v3, with the distributor valve in the position Fig. 8, a section taken on line 88 of Fig. 4, showing the segmental groove in thedistributor valve in position .to feed motive idiuid to the right end of the hammer cylin er;,' v Fig. 9, a similarview showing these mental groove in position to feed the fluid to the left end of the cylinder;

Fig. 10, a perspective of the turbine ru ner and the distributor, valveor shaft;

Fig. 11, a loiigitudinalsection of the bear- Fig- 12, a sectiolron line 12-12-of Fig. 11,;

Fig... 13, asection online 13-13of showing the details erspective of the same removed} As. shown in the drawings, thebody 1 of the tool is made up of a barrel or gripe)... :In order that the tool maybe comfortably graspedin one hand and manipum of efi'ort on the part of the operator, these parts are designed to closely simulate thecorresponding parts of a standard type pistol or revolver. .This, taken with the preferably is a die-casting of extremely light. metal, such aszinc, enables'the operator to readily manipulate the tool any workingconditions. 1 I

The barrel portion of thetool, as best shown in .Fi .3, is formed :with a continuous passage t e-rethrough- 1 At its rear end this'passage. forms a piston or hammer'chamber :4, the rear end of which is closed bya pair .of

the passage forms a barrel chamber? into which slidably fits the shank8 of a chiselor' section, barrel champreferably in the form of, a pentagon. This serves to. prevent rotation of the tool in its I ymaintains itsjcutting edge alwaysin adefinite relation to'therest-ofthe tool.

Intermediate hammer cylinder 4 barrel the distributor valve, as itappearsin '05 fact that the body of thetool The forward end of l Fig. 1, ofithe chisel'or s'teeL.

2 and a stock under practically are shaped similarly from the end with the desired stroke; means is shown in Figs. 1, 3, 13 and 14 It chamber 7 is a reduced passage 10 in which an anvil or plunger 11 is located for reciprocatory movement. Anvil 11 has an enlarged head 12 which normally, that is, when the tool steel 9 is not pressing against the work, engages the left end of hammer cylinder 4, as shown in Fig.3. The length of plunger 11 is such that, when the plunger is in this position, its outer end projects a short distance 13 into barrel chamber 7 and abuts the inner endof'steel 9.

Located in chamber 4 is a hammer 14 adapted to control exhaust ports 15, 16 leading from the chamber. Inlet ports 17, 18 are provided near the ends of chamber 4, and distribution of motive fluid to these ports is controlled by certain valve mechanism to be described shortly. d

When the operator grasps the tool in his hand and forces steel 9 against the work, the

steel pushes anvil -11 inwardly until 'it assumes the dotted line position of Fig. 3. At this time, head 12 of the anvil isspaced wall of chamber 4 and steel 9 abutsthe inner end of its socket 7. Motive fluid being admitted to the right end of hammer chamber 4 through inlet 18, hammer 14 is forced to the left and delivers a blow to the head of anvil 11. This is transmitted to chisel 9 which is thereby driven into the work against the pressure exerted by the operator on the tool. The normal stroke of the tool steel is indicated by the distance 13, Fig. 3.

Improved means are provided for preventing steel 9 from dropping out of the tool. but which at the same time permit reciprocation of the steel in its socket in accordance This retaining comprises a semicircular spring member 19 perforated at each of its ends to receive the head 20 of a removable plug or pin 21.-

Spring member 19 is snapped into place about the lower side of the barrel of the tool, as shown in Figs. 3 and13, and serves to maintain the tool-steel-holding plugs 21, 21 in place in suitable openings provided inthe sides of the barrel. The inner ends of plugs 21, 21 are rounded and project sufficiently into barrel chamber 7 to engage an annular groove 22 formed in the shank 8 of the steel. Each plug 21 is formed with an annular flange 23 for properly positioning it in the opening in the barrel This flange also provides for proper interengagement between the retaining spring 19 and the plugso as to hold the latter in place. The diameter of the inner end of plug 21 and the length of the annular slot 22 in the steel are such as to preclude interference with the normal stroke or reciprocatory mpvemcnt of the steel. A continuous rib 19 is formed on the barrel. of the tool surrounding spring member 19. This serves to position the spring member and prevent its accidental removal.

The means for distributin the motive fluid to hammer chamber 4 and the exhausting of the motive fluid from this chamber will now be described. Mounted for rotation in the body of the tool transversely of hammer chamber 4 and substantially midway between its:ends is a distributor valve or shaft 24.

.This member is best shown in Figs. 3 and 4.

Shaft 24 is located within a cylindrical bearing25 fixed in a suitable'opening 26 formed in the body of the tool.

As shown in Fig. 4, the left side of the tool body is provided with an annular extension 27 which forms a turbine runner chamber 28. The left end of valve shaft 24 extends into chamber 28 and has arunner 29 fixed thereon.

Runner 29, as shown in detail in Fig. 10, I

is provided on its inner face with buckets against whichthe exhaust fluid fronrhammer chamber 4 is adapted to impinge, as explained later, in order to rotate the runner and the shaft or valve 24 to which itis attached. The parts are arranged so as to cause runner 29 to rotate in a counterclockwise -direction, as viewed in Figs. 1 and 3. 'An annular flange 31 at the inner ends of runner buckets 30'prevents escape of the fluid at this point. As a result, the fluid flows from the periphery of the runner and passes out of the exhaust port 32 provided in the side of runner chamber 28', see Figs. 1 and 2.

v The outer side of runner chamber 28 is closed by a cover plate 33, which preferably is threaded into body extension 27. Spanner Wrench depressions 34, 35 are provided for removing or replacing cover 33. Centrally of theinnerside of the cover plate, a. socket 36 is formed to receive a ball bearing 37. When the cover plate is in place,= bearing engages the inner end of shaft 24 'diametricallyopposed openings 41, 42 in the sides of valve bearing 25. In this manner, motive fluid is distributed either by way of inletpassage'43 to inlet port 17 at the left end of hammer chamber 4, or by Way of inlet passage 44 to inletxport 18 opening into the right end of the hammer chamber. At-

tention is. directed to the fact that, as shown in Figs. 8 and 9, inlet passage 43 and openof hammer chamber 4 are :of smaller diameter than bearing opening 42 and passage 44 ing 41 in bearing 25 leading to the left end leading to the right end ofthe chamber. {This is for the purpose of restricting the I flow of I paratory to its nextiworkingstroke.

1 cred-to this point The motive fluid from the source of supply is delivered todistributor valve 24-by means of an upright passage 45 in the bane dle, of the tool, which connects at its upper end to an opening 46 in theunder side of valve bearing25t The motive fluidfdelivpassesinto annular groove 38 in shaft 24 (F ig. 3)','and thence to segmental. groove 39 by way of groove 40 (Fig.

4), the fluid being distributed'by the segmental groove to theopposit-e ends of. hammer-chamber 4, as explained. ab0ve.- v

'The motive fluid is furnished to the tool byway of a passage 47 in the handle3 to i the'lower end ofwhicha'hose 48 leading from covered, bysm'd earlier application. I

a source of pressure fluidsupply is connected. The motive fluid flows frompassage .47 into a smaller passage 49, the inner endofwhich opens into a valve chamber 50. I

As shown in Fig.3, the outer end ofthe valve chamber is closed by aslotted-screW plug 51., The inner end of valve chamber-50 connects by a, reduced. passage '52 with the lower end. of upright passage leading to the distributorvalve or shaft24.

Passage of motive fluid from valve chamber into passage 52 is. controlled by .a throttle valve53, the head of which is normally held. in closed positionfagainst valve seatz54 by means of a coil spring 55 interposed between the head of the valve and screw plug-51.. The stem 56 of the throttle valve extends slidably'thro'ugh an opening 57in the tool handle from which it projects for engagement by valve-actuating trigger 58,'see Figs. 1 and 3., Trigger 58 is carried bya pivot pin 59 mounted on'the :body of the tool. Coac ting lugs 60,61 on the barrel,

of the tool and: the"-trigger,; respectively,

serve to maintain the trigger in proper op erating relation to the stem 56 of the throttle valve. i

As stated hereinbefore, hammer, 14 con-4 r trols the exhausting of the motive fluid from chamber 4 through exhaust ports 15,16. In order to conduct the exhaust fluid from the hammer chamber to the turbine runner 29,

whereby the distributor valve 24 is actuated,-

exhaust port 15 connects at its lower end to a horizontal passage 62 (Figs. 3 and 7). At its forward end passage '62 opens into a downwardly inclined, duct 63(Fig. 6) from which the exhaust fluid is ejected against the is adapted to 'er end of crating parts of the tool;

buckets of runner 29 indicated by the arrow.. I I p L As shown in Fig.- 3, the lower end of exhaust port16 connects with a second horizontal passage 64,. the latter in turn opening into anrupwardly inclined duct 65 (Fig. 5);

From duct 65 the exhaust fluid also is ejected in order to rotate it as 7 against the buckets of runner 29 at the opposite side of the runner in order to assist in operating it. The arrangement of inlet ducts 63, 65 and exhaust port 32 is designed to circulate fluid aboutthe runner and bearing 37 to cool these parts. It will be noted that the inner ends of horizontal exhaust passages 62,

64 are located at the opening 26 in the tool me on January 30, -1931, Serial Number 512,-.

446. Certainfeatures' of the motive fluid dis.-

tributingmeans described herein are also a More efiicient lubrication of the moving parts in thepresent device is obtainedby the lubricant-supplying means" (located in fluid duct 47 in the handle. This comprises a tubular sheet metal spool 66 provided with flared ends 67, 68, for properly supporting it inpassage 47. Surrounding the-spool is a layer or winding of felt or wicking 69 which through an opening 70 in the'side of the handle, see F 4. A screw plug 71 normally closesthis port. 'The'body of spool is provided with a small opening 72 near its upper end and a similar opening 73 adjabe saturated with lubricant,

cent its lower end. Located against the low mesh screen '7 4,. which serves entrance ofiforeign material into the tool.

through spool 66. In its passage through the spool,'the fluid, due tofopenings 72, 73 inthe spool,.serves to pick up a certain amount of lubricant from the felt and carry it; in the form ofa mist through the various passages of the device. 7

Normallyfcoil spring-55 serves to main- I tain throttle valve 53 closed, thereby preventing passage of the motive fluid to the op- [of trigger .58 opens the throttle valve. As a result, motive fluid flows from valve chamber .50 past the throttle valve and cupwardly, through duct 45 into annular groove 38 of .the rotary distributing valve 24. IFromhere the .fluid'passes to segmentalgroove .39 and spool66in passage 47 is a small to prevent the In, use, operation acter, described, the combination of a tool body formed with a piston chamber having inlet and exhaust ports; a piston located in is distributed to one end or the other of hammer chamber 1 to actuate the hammer.

Movement of the hammer 14, as explained, opens either exhaust port 15 or 16, according to the position of the hammer, and the exhaust fluid is ejected alternately from ducts 63, 65-to rotate turbine runner 29 and with it the valved shaft 24. Thus, it will be seen that operation of the rotary distributor valve is positively controlled, so as to properly and rapidly feed motive fluid to the hammer chamber. It has been found that use of the particular type of distributor valve set forth herein is highly conducive to successful operation of high speed tools of the character in question ikewise, utilization of the exhaust fluid from the hammer chamber, in the manner described, to control directly the distribution of motive fluid to the hammer chamber is found to be much preferred over the, various other proposed arrangements. It is obvious that Various structural changescanbe made in the device illustrated and described herein without departing from the scope of the invention, and it is not intended .to restrict it to the means described, except as the same may be limited by the appended claims. I v, What is claimed is l V 1. In a fluid-operated hand tool of the charsaid chamber and adapted to control said exhaust ports; a rotary valve for controlling distribution of motive fluid to said inlet ports; a turbine runner attached to said valve, the exhaust ports leading to said runner for actuation thereof solely by the exhaust fluid; and valve controlled means for supplying motive fluid, only to said distributor valve. 7

2. Ina fluid-operated hand tool of the im-.

pacttype, the combination of a tool body formed with a hammer chamberhaving front and rear inlet ports; a reciprocatory hammer in said chamber adapted to control ex haust ports leading therefrom; a rotary shaft valve for controlling distribution of motive fluid to the inlet ports, said shaft valve being disposed transversely of the chamber midway between the inlet ports; a turbine runner fixed on said shaft valve in a compartment in the tool body at one side of the chamber, the exhaust ports leading to said runner to actuate the latter solely by the exhaust fluid, said tool body being formed with a'relatively large passage leading from said rotary valve to the rear inlet port and a relatively small passage leading from said valve to the front inlet port; and valve means for feeding motive fluid only to'the distributor valve. v

3. In a. fluid pressure operated hand tool, the combination of a tool body having a piston chamber provided with inlet and outlet ports; a'piston in said chamber for controlling said outlet ports ;pressure fluid distributormeans for said cylinder; a turbine runner times during operation of the tool and means for conducting pressure'fluid to the distributor means.

4. In a pressure fluid operated hand tool of the impact'type, the'combination of a tool body provided with a motor chamber having inlet ports leading thereto; a piston located in said chamber and adapted to control exhaust ports leading therefrom; means for controlling distribution of motive fluid to said inlet ports, said means including a turbine runner and a ported shaft therefor arranged for operation solely by the exhaust fluid from said chamber; and valve means for supplying motive fluid only to said distributing means.

5. In a fluid-operated hand tool ofthe type described, tlieeombination of a tool body formed with a piston chamber having fluid inlet means and fluid exhaust means; a piston leading to said fluid motor for actuation thereof solely by the exhaust fluid; and

valve controlled means forsupplying motive fluid only to said distributor valve.

6. In a fluid-operated hand tool of the impact type, the combination of a tool body having a'hammer chamber provided with inlet and exhaust ports; a reciprocatory hammer in said chamber for controlling escape of fluid from all of said exhaust ports to the atmosphere; a rotary valve for controlling distribution of. motive fluid to said inlet ports; a turbine runner attached to said rotary valve, all of said exhaust ports leading to said runner and being in free communication therewith at all times to actuate vthe runner by. the entire exhaust from the hammer chamber; and valve-controlled means for supplying motive fluid only to the distributor valve. V

In testimony whereof I have signed my name to this specification.

JOHN R. HOFFMAN.

controlled 

